Oxygenase
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An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 (as in air) to it. The oxygenases form a class of oxidoreductases; their EC number is EC 1.13 or EC 1.14.
Oxygenases were discovered in 1955 simultaneously by two groups, Osamu Hayaishi from Japan and Howard Mason from the US.
There are two types of oxygenases:
- Monooxygenases, or mixed function oxidase, transfer one oxygen atom to the substrate, and reduce the other oxygen atom to water.
- Dioxygenases, or oxygen transferases, transfer both atoms of molecular oxygen (O2) onto the substrate.
Among the most important monooxygenases are the cytochrome P450 oxidases, responsible for breaking down numerous chemicals in the body.
[edit] References
- Osamu Hayaishi, Biochem Biophys. Res. Comm. 338(2005), 2-6
- Michael R. Waterman, Biochem Biophys. Res. Comm. 338(2005), 7-11
Active site - Binding site - Catalytically perfect enzyme - Coenzyme - Cofactor - EC number - Enzyme catalysis - Enzyme kinetics - Enzyme inhibitor - Lineweaver-Burk plot - Michaelis-Menten kinetics
EC1 Oxidoreductases,O+R+D/list (alcohol oxidoreductases, CH-CH oxidoreductases, peroxidase, oxygenase) - EC2 Transferases/list (methyltransferase, acyltransferase, glycosyltransferase, transaminase, phosphotransferase, polymerase, kinase) - EC3 Hydrolases/list (esterase, DNA glycosylases, glycosidase, protease, acid anhydride hydrolases) - EC4 Lyases/list (carboxy-lyases, aldolase, dehydratase, synthase, adenylate cyclase, guanylate cyclase) - EC5 Isomerases/list (mutase, topoisomerase) - EC6 Ligases/list (DNA ligase, aminoacyl tRNA synthetase)
Monooxygenases: 4-Hydroxyphenylpyruvate dioxygenase - Firefly luciferase
Dioxygenases: Aromatase - Nitric oxide synthase - CYP2D6 - CYP2E1 - CYP3A4 - Phenylalanine hydroxylase - Tryptophan hydroxylase - Tyrosine hydroxylase - Dopamine beta hydroxylase - Tyrosinase - Steroid hydroxylases